Blade holder for paper coating machines



Feb. 26, 1963 J. P. MUNTON ETAL 3,078,825

BLADE HOLDER FOR PAPER COATING MACHINES 5 Sheets-Sheet 1 Filed April 1,1960 Fla Feb. 26, 1963 .1. P. ,MUNTON ETAL 3,078,825

BLADE HOLDER. FOR PAPER comma MACHINES s Sheets-Sheet 2 Filed April 1,1960 Feb. 26, 1963 J. P. MUNTON ETAL 3,078,825

BLADE HOLDER FOR PAPER comma MACHINES 3 SheetsSheet 3 Filed April 1,1960 United States Patent 3,073,825 BLADE HGLDER FGR PAPER CGATHNGdAfIl-HNES John P. Mouton, Worcester, and Milton Dentch, Auburn,

Mass, assiguors to Rice Barton Qorporation, Worces er,

Mass, a corporation of Massachusetts Filed Apr. 1, 1960, er. No. 19,2591% Claims. (Cl. lld llii) This invention relates generally to machinesfor coating paper, and in particular it is concerned with the kind ofcoating machines that make use of a roll to lead a web of paper throughthe coating liquid, and a cooperating blade to level the coatingreceived by the web as it passes out of the liquid. This application isa continuation-in-part of our copending application Serial No. 771,- 888filed November 4, 1958, now abandoned, and entitled Blade Holder forFaper Coating Machines.

In coating machines of the type with which the present invention isconcerned, the coating liquid is disposed between the roll about whichis passed the web to be coated and a head assembly including a bladeholder to support the blade for leveling of the liquid. The web is leddownwardly through the liquid by the roll and it emerges from the liquidalong a line defined by the edge of the blade. The thickness of thecoating received by the web is determined by the contact pressurebetween the blade and the web. it is essential, therefore, that theposition of the blade be precisely adjustable, thereby to obtain thedesired thickness of the coating and to maintain close alignment of theblade with the roll so that the thickness of the coating will beuniform.

Because webs as wide as 25 feet must be accommodated, precise control ofthe position of the blade over such a width becomes a problem. A furtherproblem is to pro vide for replacement of the blade quickly and easily.Usually the blade requires replacement every twelve hours of machinerunning time. A normal rate of speed for the machine is 2500 feet perminute. Accordingly, down time for blade replacement can result in muchlost production which may mean the difference between a profit and lossfor the run.

The general object of the present invention, therefore, is to provide animproved blade holding and adjusting mechanism for a paper coatingmachine.

A more specific object is to provide a mechanism which permitsreplacement of the blade quickly and easily.

Another object is to provide a more accurate mechanism for controllingthe position of the blade.

Still another object is to provide means for stiffening the blade.

The novel features of the invention together with further objects andadvantages thereof will become apparent from the following detaileddescription and the accompanying drawings to which it refers.

In the drawings:

FIG. 1 is a side View in elevation of the blade holding mechanism of thepresent invention;

FIG. 2 is a plan view of the blade holding mechanism on a reduced scaleand at right angles with respect to the view of FIG. 1;

FIG. 3 is a sectional view taken on line 3-3 of FIG. 2 and enlarged;

FIG. 4 is a fragmentary sectional view taken on line l-d of FIG. 3;

FIG. 5 is a side view in elevation of an alternative embodiment of theblade holding mechanism of the present invention;

FIGS. 6, 7 and 8 are sectional views taken on lines 66, 7--7, and 8-8,respectively, of FIG. 5;

FIG. 9 is a sectional view taken on line 9-9 of FIG. 6; and

Patented Feb 26, 1953 FIG. 10 is a side elevation of a cutting apparatusincluding the novel blade holding arrangement according to theinvention.

A coating machine of the general type referred to is illustrated in FIG.10 of the drawings comprising coating roll 1 over which the web of paperis passed to be coated. The coating liquid is held in what might betermed a trough formed in part with the roll 1 and in part with thecoating head assembly including a structural walled portion 2, and ablade holder assembly rigidly fastened thereto. Numeral 1d designatesthe blade associated with the latter which, in effect, forms the bottomof the trough.

With reference now to FIGS. 1 and 2 Where a first embodiment of theinvention is illustrated, it will be observed that the numeral 11designates an upper jaw and the numeral 12 designates a lower jaw whichis pivotally connected to the upper jaw by a row of threaded members 13having hemispherical bearing portions 13'. Holding the jaws closed onthe blade 14 for leveling the coating liquid is an inflatable tube 15disposed between the jaw 12 and a spacer member 16' which bears againstthe jaw 11 rearwardly of the threaded members 13. That is to say, tube15 is comprised of a material such as rubber and is connected to asource of pressure fluid such as air. Urging the jaws to open is a rowof compression springs 2b which are retained on studs 17. One end ofeach spring it bears against the under surface of jaw 12 and the otherend bears against a washer 18 backed by a nut 19. As shown, clearance isprovided in jaw 12 for the studs 17, while threaded bores are providedin jaw 11 to engage the same.

With reference now to FIGS. 3 and 4 it will be observed that the frontof jaw 12 is formed with a non-integral tip 22 fastened by bolts 21 andthat jaw 11 is provided with a longitudinal groove 23, slightlyrearwardly of the tip 22. Disposed between the jaws in this region is amovable member 24 and a pair of blade-rigidifying members 25 and 26.Members 2-5 and 26 are fastened together by machine screws 27 with theblade 14 clamped inbetween, forwardly of the screws 27. Member 24 isprovided with a longitudinal guideway in which member 26 is retained. inaddition, member 24 is provided with a substantial clearance hole foreach threaded member 13 so that it can move forwardly and rearwardlywith respect to the aws.

To produce such movement, four uniformly spaced coupling members 28(only two of which are shown in FIG. 2) are fastened to member 24 bymeans of pins 29 having spherical bearing portions 29'. Pins 30 of likenature serve to couple each member 28 to a control member 31 having athreaded portion 31'. The latter, as shown in FIG. 1, has a nut in theform of a shaft 32 threaded onto it and the shaft is rotatably mountedin a bearing block 33. For rotation of the shaft there is provided adirect coupled hand wheel 34 and alternatively a hand wheel 35 which iscoupled to the shaft through a worm 36 and wheel 37. The hub of wheel 37together with a shoulder 32 on the shaft serve to prevent axial movementthereof so that member 31 and hence members 28 and 24 are caused to movebackwards and forwards upon rotation of the shaft. As best shown in FIG.4, member 28 is guided in its movement by the upstanding central portionof the spacer member 16 which is rigidly fastened to jaw 11 by means ofmachine screws 41. Finally there is provided a set screw 42 optionallyto lock the member 31 in place.

In operation, when it is desired to change blades, tube 15 is opened toexhaust by any convenient means to collapse it, whereupon the forceholding the rearward portions of the jaw apart is removed. Inconsequence, the jaws are caused to snap open forwardly of the threadedmembers 13 under the influence of springs 26 which act on the rearwardportions. With the jaws open, the blade assembly including the blade andthe rigidifying members is no longer held tightly in the channel definedby the movable retaining member 24, and can be readily pulled outsideways from between the jaws. At the same time a new blade assemblycan be inserted into the channel from the opposite side of the holder.Once this has been done, re-inflation of the tube clamps the new bladeassembly in place and adjustment of the screw mechanisms described indetail in the foregoing establishes the desired alignment and exposureof the blade.

In FIGS. -9 is shown another embodiment of the invention which is seento comprise an upper jaw designated 121 and a lower jaw designated 122.As shown, the jaws 121 and 122 are relieved so as to form in combinationa generally rectangular guideway or slot 127 extending longitudinallythereof. In the slot, there is a movable retaining member 128 and a pairof rigidifying members 129, 131 like those of FIGS. 1-4, which arejoined by means of screws 132. The assembly of the members 129 and 131with the blade 14 is fitted in a channel in the memher 128 where it isheld in place by the clamping action of the jaws 121122. This is bestshown in FIG. 9.

FIGS. 6, 7 and 9 illustrate in detail the mechanism for controlling theblade edge exposure in this embodiment. Thus from FIG. 6 it will beobserved that the blade adjusting member 128 is provided with a seriesof longitudinally spaced slots, the major axes of the slots extendingparallel to one another and at an angle to the longitudinal axis of themember. Disposed in the slots, as best shown in FIG. 9, are studs 141which pass through the lower jaw 122 and are threaded into the upper jaw121. Studs 141 are provided with intermediate body portions 141' ofcylindrical contour for sliding contact with the walls of the slots, andthere are nuts 142 threaded over the exposed ends of the studs. The nutsclamp the jaws together and prevent the studs from turning.

Adjacent either end of the jaws 121, 122, which extend for the width ofthe roll, there is provided a fixed mounting arm 144. Each arm 144 has aportion which is shaped in the manner of an open-ended wrench. Theseportions retain clevises 143 which are pivotally connected to the endsof the member 128. A nut 151 is threaded onto the shank end of one ofthe clevises bringing a spherical washer 152 tightly against a matingseat formed in one of the arms. A similar arrangement exists at theother arm except that a helical compression spring 153 is used betweenthe spherical washer and the nut.

As best shown in FIG. 8, one of the arms 144 also mounts a shaft 161having at one end a handle portion 162 extending at right angles to theaxis of the shaft. To the other end of the shaft is fixed a stop. Withthe handle down, the stop is in the way of the blade so that when theblade assembly is inserted from one end of the holder it cannot bepushed beyond a longitudinally centered position. With the handle up,the stop is out of the way of the blade so that it can be pulled outfrom the opposite end of the holder while a new blade is being inserted.As is apparent, at similar stop arrangement can be used with theembodiment of FIGS. l-4 if desired.

Once the assembly of the blade and rigidifying members is longitudinallycentered in the holder, the desired exposure of the blade can be readilyestablished by ad justment of the nut 151. That is to say, as the nut151 is tightened (the one remote from the spring 153), the member 128 isdrawn sideways and at the same time forwardly, the member beingconstrained to move in this manner by the bodies of the studs 141 whichride in the slots. Conversely, when the nut 151 is loosened, the

member 128 is moved in the opposite direction under the influence of thespring 153.

Although the invention has been described in connection with twoembodiments, those skilled in the art will recognize that various otherembodiments are possible which are within the scope of the invention.Therefore, the invention should not be deemed to be limited to thedetails of what has been described herein by way of example, but ratherit should be deemed to be limited only by the appended claims.

What is claimed is:

1. A blade-holding device for a paper coating machine of the trailingblade type, said device comprising a pair of elongated jaws defining alongitudinal guideway of generally rectangular section, said jaws beingadapted to clamp between them a blade with its forward edge exposed andits rearward edge extending into the region of said guideway, a pair ofrigidifying bars disposed in said guideway on either side of the blade,means to join said rigidifying bars tightly together with the bladeclamped inbetween, a movable member in sliding engagement with oppositewalls of said guideway, said movable member defining a channel forsliding engagement with at least one of said rigidifying bars, therebyto permit the combination of the blade and said bars to be withdrawnsideways from said jaws While said movable member remains stationary,and means to move said movable member forwardly and backwardly in saidguideway and thereby vary the edge exposure of said blade.

2. A blade-holding device for a paper coating machine of the trailingblade type, said device comprising a pair of elongated jaws defining alongitudinal guideway of generally rectangular section, a blade clampedbetween said jaws with its forward edge exposed and its rearward edgeextending into the region of said guideway, -a pair of rigidifying barsdisposed in said guideway on either side of said blade, means to joinsaid rigidifying bars tightly together with the blade clamped inbetween,a movable member in sliding engagement with opposite walls of saidguideway, said movable member defining a channel for sliding engagementwith at least one of said rigidifying bars thereby to permit thecombination of the blade and said bars to be withdrawn sideways fromsaid jaws while said movable member remains stationary, and means tomove said movable member forwardly and backwardly in said guideway andthereby vary the edge exposure of said blade.

3. A blade-holding device for a paper coating machine of the trailingblade type, said device comprising a pair of elongated jaws defining alongitudinal guideway of generally rectangular section, said jaws beingadapted to receive a blade with its forward edge exposed and itsrearward edge extending into the region of said guideway, 21 pair ofrigidifying bars disposed in said guideway on either side of the blade,means to join said rigidifying bars tightly together with the bladeclamped inbetween, a movable member in sliding engagement with oppositewalls of said guideway, said movable member defining a channel forsliding engagement with at least one of said rigidifying bars, therebyto permit the combination of the blade and said bars to be withdrawnsideways from the jaws while said movable member remains stationary,means pivotally connecting said jaws rearwardly of said rigidifyingmembers, an inflatable tube disposed between said jaws rearwardly ofsaid pivotal connecting means, said tube acting to force the jaws apartin this region and to urge them together forwardly of said pivotalconnectron, spring-biasing means tending to oppose the action of saidinflatable tube so that when the tube is deflated, the jaws will openforwardly of said pivotal connecting means, and means to move saidmovable member forwardly and backwardly in said guideway and therebyvary the edge exposure of said blade.

4. A blade-holding device for a paper coating machine of the trailingblade type, said device comprising a pair of elongated jaws defining alongitudinal guideway of generally rectangular section, said jaws beingadapted to receive a blade with its forward edge exposed and itsrearward edge extending into the region of said guideway,

acreage a pair of rigidifying bars disposed in said guideway on eitherside of the blade, means to join said rigidifying bars tightly togetherwith the blade clamped inbetween, a movable member in sliding engagementwith opposite walls of said guideway, said movable member defining achannel for sliding engagement with at least one of said rigidifyingbars, thereby to permit the combination of the blade and said bars to bewithdrawn sideways from the jaws while said movable member remainsstationary, means pivotally connecting said jaws rearwardly of saidrigidifying members, an inflatable tube disposed between said jawsrearwardly of said pivotal connecting means, said tube acting to forcethe jaws apart in this region and to urge them together forwardly ofsaid pivotal connection, and a mechanism to move said movable memberforwardly and backwardly in said guideway and thereby vary the edgeexposure of said blade, said mechanism including a link pivotallyconnected to said movable member, a threaded member operativelyconnected to said link, an axially fixed nut in threaded engagement withsaid threaded member, and manually operable means to turn said nut.

5. A blade-holding device for a paper coating machine of the trailingblade type, said device comprising a pair of elongated jaws defining alongitudinal guideway of generally rectangular section, a blade clampedbetween said jaws with its forward edge exposed and its rearward edgeextending into the region of said guideway, a pair of rigidifying barsdisposed in said guideway on either side of said blade, means to joinsaid rigidifying bars tightly together with the blade clamped inbetween,a movable member disposed in sliding engagement with opposite walls ofsaid guideway and defining a channel to slidably retain at least one ofsaid bars so that the combination of said blade and said bars can bemoved independently and withdrawn from the holder, said movable memberbeing provided with longitudinally spaced slots extending parallel toone another and at an acute angle to the longitudinal axis of saidmember, a plurality of cylindrical elements extending between said jawsand through the respective slots in said movable member, and means tourge said movable member longitudinally of said guideway while at thesame time permitting for ward and backward movement thereof.

6. A blade-holding device for a paper coating machine of the trailingblade type, said device comprising a pair of elongated jaws defining alongitudinal guideway of generally rectangular section, a blade clampedbetween said jaws with its forward edge exposed and its rearward edgeextending into the region of said guideway, a pair of rigidifying barsdisposed in said guideway on either side of said blade, means to joinsaid rigidifying bars tightly together with the blade clamped inbetween,a movable member in sliding engagement with opposite walls of saidguideway for moving the blade in and out and exposing more or less ofits active edge, said movable member being provided with longitudinallyspaced slots extending parallel to one another and at an acute angle tothe longitudinal axis of said member, a plurality of cylindricalelements extending between said jaws and through the respective slots insaid movable member, a threaded element pivotally connected to each endof said movable member, a pair of mounting arms carried on said machinedisposed adjacent the ends of said jaws and provided with clearanceholes to receive said threaded elements, a helical compression springretained on the free end of one of said threaded elements, means tocompress said spring against the arm adjacent thereto, and a nutthreaded onto the free end of the other of said threaded elements to actupon the arm supporting the latter and to urge said movable memberlongitudinally and transversely of said guideway.

7. A blade holding device for a paper coating machine of the trailingblade type, said device comprising a pair of elongated jaws definingtherebetween a guideway, said jaws being adapted to receive a bladeassembly comprising a blade with its forward edge exposed and itsrearward edge extending into the region of said guideway, and a barsupport to which the blade is fastened extending along the length of theblade and arranged to ride in said guideway, a movable member in slidingengagement with the walls of said guideway for forward and backadjustment relative to said jaws, said movable member defining alongitudinal guideway for said bar support thereby to permit said bladeassembly to be withdrawn sideways from the jaws while said movablemember remains stationary, means pivotally connecting said jawsrearwardly of said guideway and bar support, spring means urging saidjaws relatively from one to the other of two alternative open andclamping positions, pneumatic means operable to move the jaws againstthe bias of said spring means to the other said position, and means toadjust said movable member and blade assembly therewith in a forward andback direction in said jaws.

8. A blade holding device for a paper coating machine of the trailingblade type according to claim 7 in which the means pivotally connectingsaid jaws comprises a series of posts mounted from one of said jaws, andswivel bearings connecting the posts and the other of said jaws.

9. A blade holding device for a paper coating machine of the trailingblade type according to claim 8 in which said movable member comprises abar extending the length of the jaws having forward and back slots toreceive said posts, and the rear portion is tapered to permit therocking of the jaws to said open position, and said means to adjust saidmovable member and blade assembly therewith in a forward and backdirection comprises a plurality of rearwardly extending links connectedwith said member, a fine adjustment screw and nut connection with eachof said links, and a coarse adjustment screw extending longitudinally ofsaid jaws having a worm and screw connection with each of said fineadjustment screw and nut connections.

10. A blade holding device for a paper coating machine of the tradingblade type according to claim 7 in which said pneumatic means comprisesan inflatable tube disposed between said member and one of said jaws tooppose the bias of said spring means adapted to be inflated and deflatedto move the jaws relatively against and with the bias of the springmeans.

References Cited in the file of this patent UNITED STATES PATENTS1,892,214 Lodding Dec. 27, 1932 2,117,032 Lodding May 10, 1938 2,273,021COX Feb. 17, 1942 2,328,183 Barrett Aug. 31, 1943 2,399,688 Metzner etal. May 7, 1946 2,914,788 Smith et a1. Dec. 1, 1959

1. A BLADE-HOLDING DEVICE FOR A PAPER COATING MACHINE OF THE TRAILINGBLADE TYPE, SAID DEVICE COMPRISING A PAIR OF ELONGATED JAWS DEFINING ALONGITUDINAL GUIDEWAY OF GENERALLY RECTANGULAR SECTION, SAID JAWS BEINGADAPTED TO CLAMP BETWEEN THEM A BLADE WITH ITS FORWARD EDGE EXPOSED ANDITS REARWARD EDGE EXTENDING INTO THE REGION OF SAID GUIDEWAY, A PAIR OFRIGIDIFYING BARS DISPOSED IN SAID GUIDEWAY ON EITHER SIDE OF THE BLADE,MEANS TO JOIN SAID RIGIDIFYING BARS TIGHTLY TOGETHER WITH THE BLADECLAMPED INBETWEEN, A MOVABLE MEMBER IN SLIDING ENGAGEMENT WITH OPPOSITEWALLS OF SAID GUIDEWAY, SAID MOVABLE MEMBER